In general, arc welding is one of welding methods for generating an electric arc and melting a base material using the electric arc as a heat source to perform welding, and the types thereof are very diverse.
Among them, an inert gas arc welding is a method for performing welding, while supplying the inert gas to a welding part from a torch. In order to weld a special welding part in a state of being isolated from the air. Argon (Ar), helium (He), or the like which is not affected by nitrogen or oxygen in atmosphere and does not react with metal even at a high temperature is used as the inert gas, and a tungsten rod or a metal rod is used as an electrode.
Such an inert gas arc welding method is also referred to as a shield arc welding, and is classified into two types of a method using a heat source of a tungsten arc in an inert gas atmosphere and a method using a heat source of a metal arc. That is, there are a non-consumable type which is not melted and a consumable type which is melt depending on the electrode used as a heat source.
Here, since the non-consumable type uses a tungsten electrode rode, the non-consumable type is called a shielded inert gas tungsten arc welding or a TIG welding method. Further, since the consumable type uses a long core wire filler metal, the consumable type is called an inert gas arc welding method or a MIG welding method.
The above-mentioned MIG welding continuously supplies the consumption electrode wire substantially the same material as the base metal and melts the electrode wire and the base material by arc heat generated between the base metal and the welding wire in the inert gas to join the metal. The MIG welding commonly uses a DC welding power supply and performs using reverse polarity (welding rod +, base material −).
On the other hand, at the time of welding, while beads are generated at the welding part between the base materials, slag can be covered on the beads. Since the slag covered with the welding bead corresponds to welding defect, the slag needs to be removed immediately after welding.
Since the MIG welding has a higher melting speed and solidification speed than other welding methods, there is no time margin in which gas and impurities float, and an occurrence rate of sputtering or welding slag is small. However, there is an inconvenience in which the fixed type slag generated once is classified as a defect and the slag needs to be removed manually after visually checked by an operator in a subsequent treatment process.
Therefore, conventionally, in order to read the slag which is the defect of the welding part, after visually checking the resulting product after welding, when the slag covered by the welding bead is checked, the slag is removed manually with another impact tool, which hinders the automation of the welding process. Also, manpower is wasted and the production efficiency drops for the slag readings and removal, and slugs that have already solidified may not be broken often. Thus, there was problem of discard of product due to defects in welding products or cracks.
Therefore, there is a need for a welding device capable of preventing welding failure due to slag generation and performing the stable welding without stopping welding, monitoring slag generated at the time of welding in real time and removing the slag.